Added clock time

tests/RuntimeClockTests.cpp

@@ -0,0 +1,50 @@
+#include "RuntimeClock.h"
+
+#include <cmath>
+#include <iostream>
+
+namespace
+{
+int gFailures = 0;
+
+void Expect(bool condition, const char* message)
+{
+	if (condition)
+		return;
+
+	std::cerr << "FAIL: " << message << "\n";
+	++gFailures;
+}
+
+void TestUtcSecondsOfDay()
+{
+	const RuntimeClockSnapshot midnight = MakeRuntimeClockSnapshot(0);
+	Expect(midnight.utcTimeSeconds == 0.0, "Unix epoch starts at UTC midnight");
+
+	const RuntimeClockSnapshot midday = MakeRuntimeClockSnapshot(12 * 3600 + 34 * 60 + 56);
+	Expect(midday.utcTimeSeconds == 45296.0, "UTC time of day is seconds since midnight");
+}
+
+void TestOffsetLooksLikeTimezoneOffset()
+{
+	const RuntimeClockSnapshot snapshot = MakeRuntimeClockSnapshot(12 * 3600);
+	Expect(std::fmod(snapshot.utcOffsetSeconds, 60.0) == 0.0, "UTC offset is minute-aligned");
+	Expect(snapshot.utcOffsetSeconds >= -14.0 * 3600.0 && snapshot.utcOffsetSeconds <= 14.0 * 3600.0,
+		"UTC offset is in the normal timezone range");
+}
+}
+
+int main()
+{
+	TestUtcSecondsOfDay();
+	TestOffsetLooksLikeTimezoneOffset();
+
+	if (gFailures != 0)
+	{
+		std::cerr << gFailures << " RuntimeClock test failure(s).\n";
+		return 1;
+	}
+
+	std::cout << "RuntimeClock tests passed.\n";
+	return 0;
+}